The term was coined by the U.K.'s Bath Film Festival director Holly Tarquini in 2014, after she noticed less than 5% of that year's top 250 films were directed by women.

She began using the F-rating alongside the typical forms of movie ratings at her festival, according to the campaign's website. It has since been adopted by other festivals.

"It's always exciting when new organisations [sic] decide they want to join us in shining a light both on the brilliant work women are doing in film and on how far the film industry lags behind most other industries when it comes to providing equal opportunities to women," Tarquini said in a statement back in January. "But our real goal is to reach the stage when the F-Rating is redundant because 50% of the stories we see on screen are told by and about film's unfairly under-represented half of the population: women."